Ketamine, a nightclub drug popularly known as Special K could offer hope to people with severe or suicidal depression.
In a recent study, researchers in Britain gave 28 people with treatment-resistant depression ketamine intravenously over three weeks and found that for many of them, the drug relieved their depression in a matter of hours.
This was true even for people who hadn't responded to other treatments, like talk therapy or antidepressants. Antidepressants can take more than a month to kick in, and don't work for everyone with major depression.
The University of Oxford researchers found that although many people in the study relapsed within a day or two, 29 percent had benefit which lasted at least three weeks and 15 percent took over two months to relapse.
Study author Dr. Rupert McShane says, "We've seen remarkable changes in people who've had severe depression for many years that no other treatment has touched. It's very moving to witness."
The study was published in the Journal of Psychopharmacology.
"Patients often comment that that the flow of their thinking seems suddenly freer. For some, even a brief experience of response helps them to realise that they can get better and this gives hope," McShane says.
Ketamine was developed in the 1960s as an anesthetic and pain reliever and is often used by veterinarians on animals. When taken in high doses as a club drug, ketamine can cause a dissociative effect that puts people in a so-called "K-hole," where they feel detached and experience distortions in how they perceive sights and sounds.
The U.S. government classifies ketamine as a Schedule III drug, meaning they have moderate to low potential for physical and psychological dependence.
CBS News reports the British study is the latest to suggest ketamine may help people with severe clinical depression who aren't helped by antidepressants.
A 2013 study led by researchers at Mount Sinai Medical Center in New York, involving 72 patients with treatment-resistant depression, found almost 64 percent of patients showed improvements in symptoms within 24 hours, and 46 percent had improved symptoms one week later.
In 2012, Yale researchers reported ketamine could treat depression by spurring the release of the neurotransmitter glutamate in the brain, which triggers the growth of synapses, or spaces between nerves that allow information to flow from one nerve cell to another. Chronic stress and depression damages these synapses, the researchers stated at the time, but a single dose of ketamine may rapidly reverse the damage. However, the improvement that's seen within hours may last only a week to 10 days, they warned at the time.
NPR News quotes Christopher Stephens, who had tried lots of medications for his depression without success. He says he felt better after a single dose of ketamine.
"Monday afternoon I felt like a completely different person," he says. "I woke up Tuesday morning and I said, 'Wow, there's stuff I want to do today.' And I woke up Wednesday morning and Thursday morning and I actually wanted to do things.
I wanted to live life."